Abstract
A natural antibody with binding specificity for recombinant tissue-type plasminogen activator (t-PA) expressed in mouse C127 cells was present in almost all disease-free humans and patients with thrombotic disease examined. This antibody was specific for a carbohydrate, α1-3-linked galactose residue, and was isolated by affinity chromatography using Synsorb 90 coupled with the glycosidic epitope Galα1-3Galβ1-4Glc-R as an immunoadsorbent. The evaluation of various glycoproteins for ability to bind the purified antibody in ELISA demonstrated that not only recombinant t-PA from C127 cells but also recombinant erythropoietinc (EPO) and recombinant protein C produced in C127 cells have α1-3-linked galactose residues on their sugar side chains. This anti-α-galactosyl antibody also interacted with natural t-PA from human vascular trees (vascular t-PA) and placenta (placent t-PA), but not to melanoma t-PA, recombinant t-PA, EPO or protein C expressed in Chinese hamster ovary (CHO) cells.
